Closed-chest coronary artery bypass grafting on the beating heart with the use of a computer-enhanced surgical robotic system

A review on tele-manipulators for remote diagnostic procedures and surgery

With modern medicine and healthcare services improving in leaps and bounds, the integration of telemedicine has helped in expanding these specialised healthcare services to remote locations. Healthcare telerobotic systems form a component of telemedicine, which allows medical intervention from a distance. It has been nearly 40 years since a robotic technology, PUMA 560, was introduced to perform a stereotaxic biopsy in the brain. The use of telemanipulators for remote surgical procedures began around 1995, with the Aesop, the Zeus, and the da Vinci robotic surgery systems. Since then, the utilisation of robots has steadily increased in diverse healthcare disciplines, from clinical diagnosis to telesurgery. The telemanipulator system functions in a master–slave protocol mode, with the doctor operating the master system, aided by audio-visual and haptic feedback. Based on the control commands from the master, the slave system, a remote manipulator, interacts directly with the patient. It eliminates the requirement for the doctor to be physically present in the spatial vicinity of the patient by virtually bringing expert-guided medical services to them. Post the Covid-19 pandemic, an exponential surge in the utilisation of telerobotic systems has been observed. This study aims to present an organised review of the state-of-the-art telemanipulators used for remote diagnostic procedures and surgeries, highlighting their challenges and scope for future research and development.

Historical evolution of robot-assisted cardiac surgery: a 25-year journey

Many patients and surgeons today favor the least invasive access to an operative site. The adoption of robot-assisted cardiac surgery has been slow, but now has come to fruition. The development of modern surgical robots took surgeons close collaboration with mechanical, electrical, and optical engineers. Moreover, the necessary project funding required entrepreneurs, federal grants, and venture capital. Non-robotic minimally invasive cardiac surgery paved the way to the application of surgical robots by making changes in operative approaches, instruments, visioning modalities, cardiopulmonary perfusion techniques, and especially surgeons' attitudes. In this article, the serial development of robot-assisted cardiac surgery is detailed from the beginning and through clinical application. Included are references to the historical and most recent clinical series that have given us the evidence that robot-assisted cardiac surgery is safe and provides excellent outcomes. To this end, in many institutions these procedures now have become a new standard of care. This evolution reflects Sir Isaac Newton's famous 1676 quote when referring to Rene Descartes, "If have seen further [sic] than others, it is by standing on the shoulders of giants".

Multi-Spectrum Robotic Cardiac Surgery: Early Outcomes

Objective

The robotic cardiac surgery program at our current institution began in 2013 with an experienced and dedicated team. This review analyzes early outcomes in the first 1103 patients.

Methods

We reviewed all robotic procedures between July 2013 and February 2021. Primary outcomes were mortality and perioperative morbidity. Our robotic approach is totally endoscopic for all cases: off-pump for coronary and epicardial procedures, and on-pump with the endoballoon for mitral valve and other intracardiac procedures.

Results

There were 1103 robotic-assisted cardiac surgeries over 7 years. A total of 585 (53%) were off-pump totally endoscopic coronary artery bypasses, 399 (36%) intracardiac cases (including isolated and concomitant mitral valve procedures, isolated tricuspid valve repair, CryoMaze, atrial or ventricular septal defect repair, benign cardiac tumor, septal myectomy, partial anomalous pulmonary venous drainage, and aortic valve replacement); 80 (7%) epicardial electrophysiology-related procedures (epicardial atrial fibrillation ablation, left atrial appendage ligation, lead placement, and ventricular tachycardia ablation); and 39 (4%) other epicardial procedures (pericardiectomy, unroofing myocardial bridge). Mortality was 1.2% (observed/expected ratio, 0.7). In the totally endoscopic coronary artery bypass and intracardiac groups, mortality was 1.0% (observed/expected, 0.6) and 1.5% (observed/expected, 0.87), respectively. There were 8 conversions to sternotomy (0.7%) and 24 (2.2%) take-backs for bleeding. Mean hospital and intensive care unit lengths of stay were 2.74 ± 1.26 days and 1.28 ± 0.57 days, respectively.

Conclusions

This experience demonstrates that a robotic endoscopic approach can safely be used in a multitude of cardiac surgical procedures both on- and off-pump with excellent early outcomes. An experienced surgeon and team are necessary. Longer-term follow-up is warranted.

Robotic off-pump totally endoscopic coronary artery bypass in the current era: report of 544 patients

OBJECTIVES

Robotic off-pump totally endoscopic coronary artery bypass (TECAB) is the least invasive form of surgical coronary revascularization. It has proved to be highly effective and safe. Its benefits are well-established and include fewer complications, shorter hospital stay and quicker return to normal activities. TECAB has undergone 2 decades of technological advancement to include multivessel grafting, a beating-heart approach and successful completion in multiple patient groups in experienced hands. The aim of this report was to examine outcomes of robotic off-pump TECAB at our institution over 7 years.

METHODS

Data from 544 patients undergoing TECAB between July 2013 and August 2020 were retrospectively examined. The C-Port Flex-A distal anastomotic device was used for the majority of grafts (70%). Yearly follow-up was conducted. Angiographic early patency data were reviewed for patients undergoing hybrid revascularization.

RESULTS

The mean age was 66 years, with 1.7% mean STS risk. Fifty-six percentage had multivessel TECAB. There was 1 conversion to sternotomy, and 46% extubation in the Operating Room (OR). Mortality was 0.9%. Early graft patency was 97%. At mid-term follow-up at 38 months, cardiac mortality was 2.7% and freedom from major adverse cardiac events was 92.5%.

CONCLUSIONS

We conclude that robotic beating-heart TECAB in the current era is safe and effective with excellent outcomes and comparable early angiographic patency to standard coronary artery bypass grafting surgery when performed frequently by an experienced team. This procedure was completed in our hands both with and without an anastomotic device. Longer-term studies are warranted.

Minimally invasive and robotic coronary artery bypass grafting-a 25-year review

During the mid-1990s cardiac surgery started exploring minimally invasive methods for coronary artery bypass grafting (CABG) and has over a 25-year period developed highly differentiated and less traumatic operations. Instead of the traditional sternotomy mini-incisions on the chest or ports are placed, surgery on the beating heart is applied, sophisticated remote access heart lung machine systems as well as videoscopic units are available, and robotic technology enables completely endoscopic approaches. This review describes these methods, reports on the cumulative intra- and postoperative outcome of these procedures, and gives an integrated view on what less invasive coronary bypass surgery can achieve. A total of 74 patient series published on the topic between 1996 and 2019 were reviewed. Six main versions of minimal access and robotically assisted CABG were applied in 11,135 patients. On average 1.3±0.6 grafts were placed and the operative time was 3 hours 42 min ± 1 hour 15 min. The procedures were carried out with a hospital mortality of 1.0% and a stroke rate of 0.6%. The revision rate for bleeding was 2.5% and a renal failure rate of 0.9% was noted. Wound infections occurred at a rate of 1.2% and postoperative hospital stay was 5.6±2.2 days. It can be concluded that less invasive and robotically assisted versions of coronary bypass grafting are carried out with an adequate safety level while surgical trauma is significantly reduced.

Robotic totally endoscopic coronary artery bypass grafting: current status and future prospects

Introduction: Totally endoscopic coronary artery bypass grafting (TECAB) can only be performed in a reproducible manner using robotic technology. This operation has been developed for more than 20 years seeing three generations of surgical robots. TECAB can be carried out beating heart but also on the arrested heart. Single and multiple grafts can be placed and TECAB can be combined with percutaneous coronary intervention in hybrid procedures.Areas covered: This review outlines indications for the procedure, the surgical technique, and the postoperative care. Intra- and postoperative results as available in the literature are reported. Further areas focus on technological development, training methods, learning curves as well as on cost. Finally, we give an outlook on the potential future of this operation.Expert opinion: Robotic TECAB represents a complex, sophisticated but safe, and over-the-years grown procedure. Even though results seem to be in line with conventional coronary surgery worldwide adoption still has been slow probably due to procedure times, costs and learning curves. Main advantages of TECAB are minimized surgical trauma and subsequent reduction of postoperative healing time. With the current introduction of new robotic devices, a new era of procedure development is on its way.

Graft Patency after Robotically Assisted Coronary Artery Bypass Surgery

Objective

With advances in robotic instrumentation and technology, both robotically assisted minimally invasive direct coronary artery bypass (RMIDCAB) and totally endoscopic coronary artery bypass (TECAB) have been widely used over the past 20 years. Graft patency is the most important outcome in coronary bypass surgery and is associated with long-term prognosis. In this article we reviewed all experts’ studies in the field of robotic assisted coronary artery bypass and investigated graft patency in patients who underwent RMIDCAB or TECAB.

Methods

We performed a literature search in PubMed from 1999 to 2018 using the terms “Robotic” and “Coronary bypass” and/or “Minimally invasive” and/or “Totally endoscopic.” Of the articles found, studies investigating graft patency were specifically selected.

Results

In 33 articles, a total of 4,000 patients underwent robotic assisted coronary artery bypass surgery either by a RMIDCAB (2,396) or by a TECAB (1,604) approach. The graft patency was assessed by invasive angiography or computed tomographic angiography in all studies. The mean graft patency at early (<1 month), midterm (<5 years), and long-term (>5 years) follow-up was 97.7%, 96.1%, and 93.2% in RMIDCAB and 98.8%, 95.8%, and 93.6% in TECAB, respectively.

Conclusions

The graft patency of robotic assisted coronary artery bypass was equivalent to reported outcomes of the conventional approach. These results should encourage the adoption of robotic approaches in coronary bypass surgery.

Robotic Totally Endoscopic Coronary Artery Bypass Grafting: Systematic Review of Clinical Outcomes from the Past two Decades

Robotic totally endoscopic coronary artery bypass grafting (TECAB) was introduced in 1998 and has over a period of two decades gradually emerged from single-vessel revascularization to multivessel bypass grafting. Dedicated centers have continuously evolved and further developed this minimally invasive method of coronary bypass surgery. A literature review was conducted to assess intra- and postoperative outcomes of TECAB. PubMed returned 19 comprehensive articles on TECAB. Investigation was focused on perioperative outcome parameters, i.e.: operative time, conversion to larger incision, revision for bleeding, atrial fibrillation, stroke, acute renal failure, and mortality. Outcome from the analysis of 2,397 reported cases showed an average operative time of 291 ± 57 minutes (range 112 to 1,050), conversion rate to larger incisions at 11.5%, and perioperative mortality at 0.8%. Pooled data demonstrated 4.2% operative revision rate due to postoperative hemorrhage, 1.0% stroke incidence, 1.6% acute renal failure, and 13.3% de novo atrial fibrillation. The mean length of hospital stay measured 5.8 ± 1.7 days. Conversion rates and operative times decreased over time. According to data in the literature, coronary bypass surgery carried out in completely endoscopic fashion utilizing robotic assistance can require relatively extensive operative times and conversion rates are somewhat higher than in other robotic cardiac surgery. However, major postoperative events lie in an acceptable range. TECAB remains the surgical revascularization method with the least tissue trauma and represents an opportunity for coronary artery bypass grafting via port access. Rates of major complications are at least similar to conventional surgical access procedures.

Robotic (super) microsurgery: Feasibility of a new master-slave platform in an in vivo animal model and future directions

Advanced microsurgical procedures are currently limited by human precision and manual dexterity. The potential of robotics in microsurgery is highlighted, including a general overview of applications of robotic assistance in microsurgery and its introduction in different surgical specialties. A new robotic platform especially designed for (super) microsurgery is presented. Results of an in vivo animal study underline its feasibility and encourage further development toward clinical studies. Future directions of robotic microsurgery are proposed.

Robotic-assisted coronary artery bypass surgery: an 18-year single-centre experience

BACKGROUND

Minimally invasive robot-assisted direct coronary artery bypass (RADCAB) has emerged as a feasible minimally invasive surgical technique for revascularization that might offer several potential advantages over conventional approaches. We present our 18-year experience in RADCAB.

METHODS

Between February 1998 and February 2016, 605 patients underwent RADCAB. Patients underwent post-procedural selective graft patency assessment using cardiac catheterization.

RESULTS

The mortality rate was 0.3%. The rate of conversion to sternotomy for any cause was reduced from 16.0% of the first 200 cases to 6.9% of the last 405 patients. The patency rate of the LITA-to-LAD anastomosis was 97.4%. Surgical re-exploration for bleeding occurred in 1.8% of patients, and the transfusion rate was 9.2%. Average ICU stay was 1.2 ± 1.4 days, and average hospital stay was 4.8 ± 2.9 days.

CONCLUSIONS

Robot-assisted coronary artery bypass grafting is safe, feasible and it seems to represent an effective alternative to traditional coronary artery bypass grafting in selected patients.

Developments in surgical revascularization to achieve improved morbidity and mortality

Coronary artery bypass graft surgery remains the main treatment modality for multivessel coronary artery disease and has consistently been demonstrated to have significantly lower rates of major adverse cardiac and cerebrovascular events in comparison to percutaneous coronary intervention. In this article we will explore the advances over time and the recent refinements in the techniques of surgical revascularization and how these contribute to the superior outcome profile associated with coronary artery bypass graft surgery. These include the current outcome status of coronary artery bypass grafting; the major landmark trials, registries and meta-analyses comparing coronary artery bypass grafting and percutaneous coronary intervention; the developments in coronary artery disease lesion classification; the techniques for the physiological assessment of coronary artery lesions; bypass grafting using arterial conduits; the role of off-pump coronary artery surgery; the outcomes of reoperative surgery; hybrid techniques for coronary revascularization; minimally invasive coronary artery surgery and finally robotic surgery.

Systematic review of robotic-assisted, totally endoscopic coronary artery bypass grafting

BACKGROUND

Advancements in surgical robotic technology over the last two decades have enabled coronary artery bypass grafting to be performed totally endoscopically, and have the potential to significantly change clinical practice in the future.

METHODS

A systematic review of studies reporting clinical outcomes of total endoscopic coronary artery bypass grafting (TECABG) was performed.

RESULTS

14 appraised studies included 880 beating heart TECABGs, 360 arrested heart TECABGs, 633 one-vessel operations and 357 two-vessel operations. Patients were generally low-risk. There was a significant learning curve. The weighted means for short-term beating heart and arrested heart TECABG results respectively were: intraoperative exclusion rate of 5.7% and 1.9%, intraoperative conversion rate of 5.6% and 15.0%, all-cause mortality of 1.2% and 0.4%, stroke of 0.7% and 0.8%, myocardial infarction of 0.8% and 1.8%, new onset atrial fibrillation of 10.7% and 5.1% and post-operative reintervention rate of 2.6% and 2.3%. The overall rate of short term postoperative graft patency for beating heart and arrested heart TECABG was 98.3% and 96.4% respectively.

CONCLUSIONS

Appropriate patient selection was important in minimizing the risk of intraoperative and postoperative complications. Short-term outcomes of both beating and arrested heart TECABG were acceptable, but results so far have been heterogeneous. There were fewer studies reporting intermediate to long-term outcomes, but results were encouraging, and further investigation and development of the procedure is warranted.

Augmented Reality Image Guidance during Off-Pump Mitral Valve Replacement through the Guiraudon Universal Cardiac Introducer

Objective

We report our experience with ultrasound augmented reality (US-AR) guidance for mitral valve prosthesis (MVP) implantation in the pig using off-pump, closed, beating intracardiac access through the Guiraudon Universal Cardiac Introducer attached to the left atrial appendage.

Methods

Before testing US-AR guidance, a feasibility pilot study on nine pigs was performed using US alone. US-AR guidance, tested on a heart phantom, was subsequently used in three pigs (~65 kg) using a tracked transesophageal echocardiography probe, augmented with registration of a 3D computed tomography scan, and virtual representation of the MVP and clip-delivering tool (Clipper); three pigs were used to test feature-based registration.

Results

Navigation of the MVP was facilitated by the 3D anatomic display. AR displayed the MVP and the Clipper within the Atamai Viewer, with excellent accuracy for tool placement. Positioning the Clipper was hampered by the design of the MVP holder and Clipper. These limitations were well displayed by AR, which provided guidance for improved design of tools.

Conclusions

US-AR provided informative image guidance. It documented the flaws of the current implantation technology. This information could not be obtained by any other method of evaluation. These evaluations provided guidance for designing an integrated tool: combining an unobtrusive valve holder that allows the MVP to function properly as soon as positioned, and an anchoring system, with clips that can be released one at a time, and retracted if necessary, for optimal results. The portability of Real-time US-AR may prove to be the ideal practical image guidance system for all closed intracardiac interventions.

History of robotic surgery

Robotic surgery is one of the most advanced forms of Minimally Invasive Surgery. Although the application of robotic technology to surgical robotics started some 20 years ago, the earliest work in robotics and automation can be traced back to 400 BC. Some of the early pioneers include Archytas of Arentum, Leonardo da Vinci, Gianello Toriano, and Pierre Jaquet-Droz, and we owe to these philosophers and scientists the fact that we can offer the benefit of minimal invasion in surgery. The purpose of this review is to give a brief description of the evolution of robotic surgery from its early history to present-day surgical robotics.

Robotic manipulators in cardiac surgery: the computer-assisted surgical system ZEUS

Minimally invasive strategies continue to evolve in cardiac surgery. Robotic-assisted systems have been introduced recently, to increase the precision of endoscopic coronary surgery. This report describes the experimental and clinical use of the computer-assisted robotic system ZEUS for endoscopic coronary artery bypass anastomoses. The ZEUS system consists of three interactive robotic arms and a control unit, allowing the surgeon to move the instrument arms in a scaled-down mode. The third arm (AESOP) positions the endoscope under voice control. The present study demonstrates the feasibility of endoscopic coronary artery bypass grafting using a computer-assisted surgical robotic system on the arrested heart, as well as on the beating heart in selected patients. However, robotic-assisted cardiac surgery is still developing, and tremendous efforts are still required to establish a routine procedure.

Robotic pyeloplasty using internet protocol and satellite network-based telesurgery

BACKGROUND

In North America, the urological community has embraced surgical robotic technology in the performance of complex laparoscopic surgery. The performance of complex long-distance telesurgery requires further investigation prior to clinical application.

METHODS

The feasibility of laparoscopic robot-assisted pyeloplasty in a porcine model was assessed using the Zeus robot and the internet protocol virtual private network (IP-VPNe) and satellite links. Eighteen pyeloplasty procedures were performed, using real-time, IP-VPNe and satellite network connection (six of each). Network and objective operative data were collected.

RESULTS

Despite network delays and jitter, it was feasible to perform the pyeloplasty procedure without significant detriment in operative time or surgical results compared with real-time surgery.

CONCLUSION

The completion of complex tasks such as robotic pyeloplasty is feasible using both land-line and satellite telesurgery. However, the clinical relevance of telesurgery requires further assessment.

Prospective angiographic comparison of direct, endoscopic, and telesurgical approaches to harvesting the internal thoracic artery

BACKGROUND

The purpose of this study was to compare the quality of left internal thoracic arteries harvested by the conventional open approach versus minimally invasive videoscopic and robotic-assisted telesurgical techniques.

METHODS

One hundred and fifty consecutive patients with single vessel coronary artery disease were prospectively studied. The left internal thoracic artery was harvested using three different approaches, with 50 patients consecutively assigned to each group. The off-pump coronary artery bypass (OPCAB) group underwent median sternotomy with direct visualization. The automated endoscopic system for optimal positioning (AESOP) group employed the AESOP 3000 system (Computer Motion Inc, Goleta, CA) for robotic-assisted visualization with endoscopic manual left internal thoracic artery harvesting. The Zeus group used the Zeus robotic telesurgical system (Computer Motion Inc) and internal thoracic artery harvesting was performed remotely from a surgical console. Postanastomotic left internal thoracic artery flows and day one postoperative angiography were used to assess internal thoracic artery quality and patency.

RESULTS

Average left internal thoracic artery harvest times were 23 +/- 2.5, 63.3 +/- 20.3, and 66.1 +/- 17.9 minutes in the OPCAB, AESOP, and Zeus groups, respectively (p < 0.001, OPCAB vs AESOP and Zeus). Intraoperative graft flows averaged 28.1 +/- 11.9, 33.7 +/- 19.3, and 36.9 +/- 24.6 mL/minute, respectively in the OPCAB, AESOP, and Zeus groups (p = 0.317, OPCAB vs AESOP and Zeus). There was no significant angiographic difference in the patency rate of the harvested left internal thoracic arteries in the three groups (p = 0.685, overall).

CONCLUSIONS

The left internal thoracic artery can be harvested safely and effectively using minimally invasive videoscopic and robotic-assisted telesurgical techniques. Although the less invasive approaches require specialized equipment and training as well as increased operative time, they offer the potential for less traumatic myocardial revascularization through smaller incisions and reduced postoperative morbidity.

Results of the Prospective Multicenter Trial of Robotically Assisted Totally Endoscopic Coronary Artery Bypass Grafting

BACKGROUND

Robotic technology has been proven safe and efficacious in the performance of mitral valve repair and atrial septal defect repair. This report describes a Food and Drug Administration-sanctioned multicenter study of the safety and efficacy of the da Vinci system (Intuitive Surgical, Inc, Mountain View, CA) for totally endoscopic coronary artery bypass (TECAB) surgery.

METHODS

Patients requiring left anterior descending (LAD) coronary artery revascularization were eligible. The procedure was performed with femoro-femoral cardiopulmonary bypass (CPB), endoaortic balloon occlusion, and thoracoscopy. All aspects of the procedure were performed with the robotic system, from internal mammary artery harvest to coronary anastomosis.

RESULTS

Ninety-eight patients requiring single-vessel LAD revascularization were enrolled at 12 centers. Thirteen patients (13%) were excluded intraoperatively (eg, failed femoral cannulation, inadequate working space). In 85 patients (69 men, age 58 +/- 10 years) who underwent TECAB, CPB time was 117 +/- 44 minutes, cross-clamp time was 71 +/- 26 minutes, and hospital length of stay was 5.1 +/- 3.4 days. There were five (6%) conversions to open techniques. There were no deaths or strokes, one early reintervention, and one myocardial infarction (1.5%). Three-month angiography was performed in 76 patients, revealing significant anastomotic stenoses (> 50%) or occlusions in 6 patients. Overall freedom from reintervention or angiographic failure was 91%.

CONCLUSIONS

Robotic TECAB was accomplished with no mortality, low morbidity, and angiographic patency and reintervention rates comparable with published data. Although the use of CPB was a limitation of the technique, this experience represents a step toward more advanced procedures, such as multivessel or off-pump TECAB.

Effect of sensory substitution on suture-manipulation forces for robotic surgical systems

OBJECTIVES

Direct haptic (force or tactile) feedback is not yet available in commercial robotic surgical systems. Previous work by our group and others suggests that haptic feedback might significantly enhance the execution of surgical tasks requiring fine suture manipulation, specifically those encountered in cardiothoracic surgery. We studied the effects of substituting direct haptic feedback with visual and auditory cues to provide the operating surgeon with a representation of the forces he or she is applying with robotic telemanipulators.

METHODS

Using the robotic da Vinci surgical system (Intuitive Surgical, Inc, Sunnyvale, Calif), we compared applied forces during a standardized surgical knot-tying task under 4 different sensory-substitution scenarios: no feedback, auditory feedback, visual feedback, and combined auditory-visual feedback.

RESULTS

The forces applied with these sensory-substitution modes more closely approximate suture tensions achieved under ideal haptic conditions (ie, hand ties) than forces applied without such sensory feedback. The consistency of applied forces during robot-assisted suture tying aided by visual feedback or combined auditory-visual feedback sensory substitution is superior to that achieved with hand ties. Robot-assisted ties aided with auditory feedback revealed levels of consistency that were generally equivalent or superior to those attained with hand ties. Visual feedback and auditory feedback improve the consistency of robotically applied forces.

CONCLUSIONS

Sensory substitution, in the form of visual feedback, auditory feedback, or both, confers quantifiable advantages in applied force accuracy and consistency during the performance of a simple surgical task.

Optimization of Vessel Orientation for Robotic Coronary Artery Bypass Grafting

The availability of telemanipulation robots has not yet resulted in the emergence of a reliable endoscopic coronary bypass procedure. A major challenge in performing a closed-chest coronary operation is creating a high-quality anastomosis in a reasonable period of time. In this experimental study, the impact of distal vessel orientation on the speed and accuracy of anastomosis was quantifed. We found that vessel orientation and the relative angle of the surgical plane influence anastomosis speed, the trauma to the vessel, the accuracy of stitch placement, and the eventual achievement of hemostasis. Our results suggest that the speed and accuracy of a robotically performed anastomosis of a vessel graft to a coronary artery can be improved by making small changes in vessel orientation. Vessels should be positioned between the horizontal and diagonal orientation and inclined between the horizontal and +45. Because the 6-o'clock stitch is particularly challenging, surgeons may benefit from an orientation that moves the heel or the toe of the anastomosis away from this critical position.

Totally endoscopic coronary artery bypass graft: initial experience with an additional instrument arm and an advanced camera system

BACKGROUND

Robotically enhanced telemanipulation for totally endoscopic coronary artery bypass does not provide adequate tactile feedback, traction, or countertraction. The exposition of coronary target sites is difficult, the visual field is limited, and the epicardial stabilization may be troublesome. A fourth robotic arm for endothoracic instrumentation has been added to the da Vinci surgical system to facilitate totally endoscopic operations. The stereoendoscope was upgraded with a wide-angle feature.

METHODS

The procedure was performed in five patients. Four of these patients had left internal thoracic artery (LITA) to left anterior descending artery (LAD) grafting on the beating heart and the fifth had sequential bypass grafting (LITA to diagonal branch and LAD) on an arrested heart. The additional effector arm of the da Vinci surgical system was brought into the operative field beneath the operating table and used as a second right arm. The wide-angle view was activated by either the console or the patient side surgeon.

RESULTS

The mean operative, port placement, and anastomotic times for a beating-heart totally endoscopic coronary artery bypass were 195 +/- 58, 25 +/- 10, and 18 +/- 5 min, respectively. All procedures were free of morbidity and mortality, with satisfactory angiographic control. The sequential arterial bypass grafting procedure was fully completed in totally endoscopic technique.

CONCLUSIONS

The additional instrumentation arm and wide-angle visualization are useful technical improvements of the da Vinci surgical system, solving the problem of traction, countertraction, and facilitated exposition of target sites as well as visualization of the surgical field. They provide potential for wider acceptance of totally endoscopic coronary artery bypass grafting in a larger surgical community.

Robotic Applications in Cardiac Surgery

Traditionally, cardiac surgery has been performed through a median sternotomy, which allows the surgeon generous access to the heart and surrounding great vessels. As a paradigm shift in the size and location of incisions occurs in cardiac surgery, new methods have been developed to allow the surgeon the same amount of dexterity and accessibility to the heart in confined spaces and in a less invasive manner. Initially, long instruments without pivot points were used, however, more recent robotic telemanipulation systems have been applied that allow for improved dexterity, enabling the surgeon to perform cardiac surgery from a distance not previously possible. In this rapidly evolving field, we review the recent history and clinical results of using robotics in cardiac surgery.

Clinical and angiographic results after mechanical connection for distal anastomosis in coronary surgery

BACKGROUND

Sutureless anastomotic devices are of increasing interest in cardiovascular surgery. We investigated the stainless steel clip system of St Jude Medical/Anastomotic Technology Group (Maple Grove, Minn) to connect saphenous vein grafts with coronary arteries.

METHODS

Forty-five patients were enrolled in this feasibility study performed on patients who had on-pump coronary artery bypass grafting, but 32 patients only received 1 distal anastomosis with this investigational device (2.5 mm [n = 14] and 2.0 mm [n = 18]). Thirteen were excluded because target vessels were too small, calcified, or tortuous. The system consists of an expandable clip mounted on a balloon catheter; delivery is obtained during balloon inflation. The main differences between the 2.5-mm and 2.0-mm devices are different loading and deployment in smaller coronary arteries for the 2.0-mm device.

RESULTS

A connecting device was deployed on the right coronary artery in 14 patients, the posterior descending branch in 12 patients, the obtuse marginal in 5 patients, and the posterolateral branch in 1 patient. Perfect hemostasis of the sutureless connector anastomosis was obtained in 28 patients. Three connectors were removed because of minor leakage at the connection site, and 1 connector was removed because of mismanipulation after successful deployment. Hand-sewn anastomosis was performed at the same arteriotomy site. Intraoperative flow was assessed by the transit time method and averaged 71 +/- 24 mL/min. One patient died of neurologic injury; the connector was patent at autopsy. One patient had a perioperative myocardial infarction. There was no adverse cardiac event in the remaining patients. All patients underwent clinical follow-up after 6 and 12 months and 35 angiograms were available in 21 patients: after 3 and 6 months, 17 anastomoses were patent and the saphenous vein graft was occluded in 4 patients.

CONCLUSIONS

The coronary connector system from St Jude Medical/Anastomotic Technology Group allows consistently uniform sutureless connection between the saphenous vein graft and coronary artery. Loading and deployment require careful training. This technology is under constant development and may give a significant boost to less invasive coronary revascularization techniques.

Clinical experience with devices for facilitated anastomoses in coronary artery bypass surgery

Recent developments in minimally invasive coronary artery surgery have been driven by the introduction of new technologies which should facilitate precise surgical maneuvers on the beating heart within confined spaces. Such technologies include coronary stabilizer systems, cardiac positioning vacuum-assisted devices, and telemanipulative systems. Despite these developments, standard suturing techniques using running polypropylene material remains a limiting factor in the surgeon's ability to perform complete revascularization with high quality anastomoses through minimal approaches to the chest cavity. Clinical validation of proximal and distal anastomotic devices has the potential to substantially improve and perhaps revolutionize minimally invasive coronary surgery. Ideal characteristics of such devices would include applicability to all conduit types, all coronary sizes, interchangeable proximal/distal sequencing of the anastomosis, and safe bail out for device malfunction. However there is an urgent need to define the performance objectives of such systems as well as the general criteria for proper and comparable evaluation and validation of different systems in animal models and subsequently in controlled prospective clinical studies. This review summarizes the most interesting systems available in both experimental and clinical settings.

Facilitated endoscopic beating heart coronary artery bypass grafting using a magnetic coupling device

BACKGROUND

Suturing of a coronary anastomosis in totally endoscopic coronary artery bypass grafting on the beating heart is technically demanding. The potential benefits of the endoscopic Magnetic Vascular Positioner device (Ventrica, Inc, Fremont, Calif) to facilitate construction of a coronary anastomosis in a closed chest environment were evaluated.

METHODS

Totally endoscopic coronary artery bypass grafting on the beating heart was performed in 8 foxhound-beagle inbred dogs with the da Vinci telemanipulation system (Intuitive Surgical, Mountain View, Calif). A prototype of the endoscopic Magnetic Vascular Positioner device was used to facilitate construction of the coronary anastomosis. One pair of magnets was inserted in the internal thoracic artery and left anterior descending artery using robotic instruments to guide and place the endoscopic delivery platform. All animals underwent angiography; gross inspection of the anastomotic site was performed after excision of the hearts.

RESULTS

The procedure was accomplished in all animals in 169 minutes (155-190 minutes). Dissection of the left anterior descending coronary artery (6.5 minutes; 1-20 minutes), positioning of the stabilizer (8.5 minutes; 7-16 minutes), placement of occlusion tapes (6 minutes, 3-10 minutes), and arteriotomy 5.5 minutes (3-30 minutes) was achieved without problems. By use of the Magnetic Vascular Positioner device, the anastomosis at the graft site was performed with the graft still in situ. Except for 1 premature deployment, all other deployments were easily accomplished in 3 minutes (1-28 minutes). The following adverse events were encountered: bleeding from the right ventricle caused by occlusion tape (1), anastomotic leakage on reperfusion requiring repair stitches (2), and anastomotic occlusion as a result of thrombus (1). All except 1 animal with a patent graft and anastomosis survived the procedure. The overall patency was 7 of 8.

DISCUSSION

The combination of robotic technology allowing for dexterous manipulation in a closed chest environment and a simple yet effective and timesaving technique for anastomotic coupling may facilitate beating heart totally endoscopic coronary artery bypass grafting.

Robotic cardiac surgery: overview

Most endoscopic procedures are excisional, not reconstructive or microsurgical, mostly because conventional endoscopic instrumentation lacks dexterity due to long, nonarticulated instruments, a fixed pivot point and counterintuitive movement of the instrument tip, and lack of depth perception. Endoscopic approaches to cardiac surgery have not been successful; however, the development of robotic surgical systems has overcome many limitations of endoscopy. Computer-assisted surgery has created a computerized digital interface between the surgeon's hands and surgical instrument tips and enhances surgical ability, thereby enabling endoscopic microsurgery. Recently, robotic systems have allowed cardiac surgeons to perform minimally invasive endoscopic coronary artery bypass grafting (CABG) and valve procedures. This article summarizes the use of robotics in cardiac surgery and discusses its potential in our specialty.

Port Placement Planning in Robot-Assisted Coronary Artery Bypass

Properly selected port sites for robot-assisted coronary artery bypass graft (CABG) improve the efficiency and quality of these procedures. In clinical practice, surgeons select port locations using external anatomic landmarks to estimate a patient's internal anatomy. This paper proposes an automated approach to port selection based on a preoperative image of the patient, thus avoiding the need to estimate internal anatomy. Using this image as input, port sites are chosen from a grid of surgeon-approved options by defining a performance measure for each possible port triad. This measure seeks to minimize the weighted squared deviation of the instrument and endoscope angles from their optimal orientations at each internal surgical site. This performance measure proves insensitive to perturbations in both its weighting factors and moderate intraoperative displacements of the patient's internal anatomy. A validation study of this port site selection was performed. cardiac algorithm also Six surgeons dissected model vessels using the port triad selected by this algorithm with performance compared to dissection using a surgeon-selected port triad and a port triad template described by Tabaie et al., 1999. With the algorithm-selected ports, dissection speed increased by up to 43% (p = 0.046) with less overall vessel trauma. Thus, this algorithmic approach to port site selection has important clinical implications for robot-assisted CABG which warrant further investigation.

Endoscopic exposure and stabilization of posterior and inferior branches using the endo-starfish cardiac positioner and the endo-octopus stabilizer for closed-chest beating heart multivessel CABG: hemodynamic changes in the pig

BACKGROUND

Closed-chest, off-pump, multivessel CABG requires modified instruments to expose and stabilize posterior and inferior coronary branches. Using three new prototype devices, we explored the feasibility of endoscopic bypass grafting on these branches and assessed cardiac function during cardiac displacement.

METHODS

Eight pigs (75 to 85 kg) were instrumented for hemodynamics and paced at 80 to 100 bpm. After closure of the sternotomy wound, the Da Vinci endoscope was inserted subxiphoidally. A sternal hook was used to hoist the sternum ventrally by 5 cm. The articulating EndoStarfish cardiac positioner was placed through a trocar (Ø12 mm). The positioner was fixed to the apex using -400 mm Hg suction and the heart was displaced anteriorly to 90 degrees. In 12 other pigs (75 to 85 kg), both internal mammary arteries (IMA) were harvested and the sternal wound was closed. Five trocar ports were placed for instrumentation (Ø12 mm, two in left chest, two in right chest, and one subxiphoidally). For coronary stabilization, a novel deployable EndoOctopus cardiac stabilizer was employed (suction -400 mm Hg). The Da Vinci robot-telemanipulator system was used for endoscopic grafting of the left and right IMA on posterior and inferior branches (16 anastomoses).

RESULTS

When circumflex arteries were fully exposed and accessible for coronary surgery, stroke volume decreased by 18%+/-3 versus baseline (P=0.02) and mean arterial pressure decreased by 27%+/-6 (P=0.001). Additional 10 degrees Trendelenburg head-down positioning normalized stroke volume and arterial pressure. In the displaced heart, obtuse marginal branches (OM) and the ramus descending posterior (RDP) of the right coronary artery became fully exposed with a mean arterial pressure >70 mm Hg during grafting. No accidental detachment occurred. Coronary target motion was restrained to approximately 1x1 mm. In two test cases, five sham distal anastomoses were created (grafts sewn to epicardium, left IMA to OM2 jump to OM3, right IMA to RDP, and composite graft from left IMA jump to diagonal branch). In 10 animals, 16 successfully completed anastomoses to RPD and OM branches of Ø1.75 to 2.5 mm required 25 to 60 minutes each to construct. At sacrifice, all anastomoses were patent.

CONCLUSIONS

In the closed-chest pig in Trendelenburg position and during lifting of the sternum, the EndoStarfish and EndoOctopus enabled IMA grafting of posterior and inferior branches on the beating heart without mean arterial pressure dropping below 70 mm Hg.

Analysis of the learning curve in telerobotic, beating heart coronary artery bypass grafting: a 90 patient experience

BACKGROUND

Recent articles have commented on the "learning curve" in robotic-assisted coronary artery bypass grafting. We systematically studied this phenomenon using standard statistical and cumulative sum (CUSUM) failure methods.

METHODS

Ninety patients underwent internal thoracic artery (ITA) takedown and an attempt at ITA to coronary bypass on the beating heart using the Zeus telerobotic system from September 1999 to December 2001. The rates of mortality and 11 predefined major complications were compared in five quintiles of 18 consecutive patients each and a CUSUM curve was generated for the entire cohort.

RESULTS

All patients but one underwent successful endoscopic ITA takedown. Thirteen patients had a totally endoscopic anastomosis, whereas in 61 a small mini-thoracotomy or mini-sternotomy was used. Sixteen patients (17.8%) were converted electively to a sternotomy: 11 patients underwent off-pump and 5 patients on-pump surgery. There were no deaths; 13 patients (14.4%) incurred one or more of the 11 major complication(s), including 5, 1, 2, 3, and 2 in each of the five quintiles (p = 0.39). Standard statistical analyses identified a significant decrease in operating room time (p < 0.0001), as well as a decrease in the incidence of an occluded graft or wrong vessel grafted from quintiles 1 to 5 (p = 0.03). On CUSUM analysis, the failure curve was steep for the first 18 to 20 patients, before moderating its slope for the remainder of the experience.

CONCLUSIONS

Robotic ITA to coronary bypass on the beating heart has a moderately steep learning curve, which is mitigated by further experience. CUSUM analysis complimented standard statistical methods in detecting a cluster of suboptimal results during the early experience with this procedure.

Telemedicine in surgery

BACKGROUND

Telemedicine is influencing surgical training, allows mentoring, proctoring and teleconferencing, and is increasingly being applied to carry out remote surgical procedures. A systematic review of the telemedicine systems available, along with a critical appraisal of their application, potential and limitations in the surgical field, has been undertaken.

METHOD

Medline, Ovid and internet searches were carried out using the keywords 'telesurgery', 'telepresence surgery' and 'telemedicine and surgery', along with hand searches of the two peer-reviewed telesurgery journals.

RESULTS

Telementoring and teleconferencing have been used widely for surgical teaching and training. Two clinical telesurgery systems are currently available and have been a trial in patients undergoing a variety of operations including cholecystectomy, coronary artery bypass, prostatectomy and gastroplasty. Most studies have reported successful outcomes but with prolonged operating times. In 2002 the first long-distance telesurgery procedure was successfully performed.

CONCLUSION

Telemedicine has huge potential to alter surgical practice but improvements are required in telesurgical technology with respect to tactile feedback, instrumentation, telecommunication speed and availability. Issues of liability, legislation, cost and benefit require clarification. The future of telemedicine in surgery may lie in facilitating complex minimally invasive techniques.

Telemanipulator-gestützte Applikation eines magnetischen Gefäß-Kopplers am schlagenden Herzen mit dem daVinci™-Surgical-System. Telemanipulatory Application of a Magnetic Vascular Coupler on the Beating Heart with the daVinci™ surgical System

The construction of a coronary anastomosis on the beating heart under totally endoscopic conditions is technically demanding. In this study the potential benefits of an endoscopic magnetic vascular coupler (MVP, Ventrica, Inc, Fremont, CA) designed to facilitate construction of a coronary anastomosis with the help of the daVinci telemanipulator (Intuitive Surgical Inc., Sunnyvale, CA) were evaluated in a totally endoscopic coronary arterial bypass (TECAB) operation on the beating heart in eight dogs. The telemanipulated instruments were used to guide and place the endoscopic MVP-application platform (prototype). All animals underwent angiography, and gross inspection of the anastomotic site was done after excision of the hearts. The procedure was accomplished in 169 minutes (155-190). With the exception of one premature deployment, all MVP-anastomoses were accomplished in 3 minutes (1-28). The following adverse events were encountered: Bleeding from the right ventricle caused by occlusion tape (1), anastomotic leakage upon reperfusion requiring repair stitches (2), anastomotic occlusion due to a thrombus (1). All but one animal that died on reperfusion despite a patent graft and anastomosis, survived the procedure. Overall patency was 7 out of 8. The combination of telemanipulator technology allowing increased manipulation dexterity in a total endoscopic environment and the effective and time saving magnetic technique for anastomotic coupling has the potential to facilitate TECAB on the beating heart.

Coronary revascularization in the 21st century. Emphasis on contributions by Japanese surgeons

The first three decades of coronary artery surgery have provided the foundation for the next century of this evolution. It is apparent that a multitude of events including the development of cardioplegia, improving surgical instrumentation, technological advances including endoscopic approaches and computer assisted robotics and biologic discoveries such as the role of the endothelium have provided the underpinnings for improved surgical outcomes. However, the single most important determinant of late results is the type of bypass conduit used for grafting. Thus, use of the left internal thoracic artery (ITA) grafted to the left anterior descending coronary is a more important determinant of survival than is any other factor (progression of coronary artery disease, increased age, poor left ventricular function, diabetes, female gender and off-pump operations). Use of two ITAs provides further benefit and it is likely that three or more arterial conduits will be shown to be advantageous in this regard in due time. Japanese cardiothoracic surgeons have made significant contributions to the continuing evolution of coronary bypass surgery and particularly to the advance of arterial conduits. This report will address those contributions to this evolution.